| to survive we need to maintain normal volume and composition of | extracellular fulid(ECF), intracellular fluid (ICF) |
| fluid balance | amout of water gained each day equals the amount lost |
| electrolyte balance | ion gain each day equals the ion loss |
| acid base balance | H+ gain is offset by their loss |
| H20 is how many percent of total body weight | 60% |
| fractions of H2O in ICF and ECF | 2/3 in ICF, 1/3 in ECF |
| largest subdivisions of ECF are | interstitial fluid of peripheral tissue, plasma of circulating blood |
| intracellular (ICF) | cytosol of cells |
| extracellular(ECF) components | plasma, interstitial fluid, lymph, CSF, other:synovial, endolymph, perilymph |
| principal ions in ECF | sodium, chloride, bicarbonate(HO3) |
| ICF contains abundance of | potassium(the main cation), negatively charged proteins |
| to maintain homeostasis the body needs to | respond to changes in the ECF, NOT the ICF |
| our cells dont | move water molecules by molecules by active transport |
| water moves....in response to..... | passively, osmotic gradients |
| the bodys content of water or electrolytes will rise if.....and will fall if.... | dietary gains exceed losses(overhydration), losses exceed gains(dehydration) |
| the main hormone for water regulation is | antidiuretic hormone (ADH) |
| increased release of ADH has two important effects | stimulates water conservation at the kidneys, reducing urinary water losses and concentrating the urine
stimulates thirst center,promoting intake of fluids |
| which part of the kidney responds to ADH | DCT, collecting ducts |
| ADH response is | increases thirst, increase water reabsorption in DCT and collecting ducts |
| in aldosterone, the higher the plama concentration of alderstone | the more effeciently the kidneys conserve Na+(reabsorb sodium and secrete potassium) |
| aldosterone is secreted in response to | rising K+ (hyperkalemia), falling Na+ levels (hyponatremia),activation of the renin-angiotensin system |
| aldosterone acts on | DCT and collecting ducts |
| whereever ..... goes....follows | sodium, water |
| the hormone atrial natriuretic peptides(ANP) is caused by | elevated blood pressure or increased blood volume |
| hormone atrial natriuretic peptides(ANP) reduces | thirst and BLOCKS the release of ADH and aldosterone |
| all the effects of ANP result in | diuresis,loose fluids in kidneys |
| edema | the movement of abnormal amounts of water from plasma into interstitial fluid |
| hyponatremia is a sign of | overhydration or water excess |
| if ECF is hypertonic | water moves from ICF-ECF |
| if ECF is hypotonic | water moves ECF-ICF |
| effects of loss of body water | severe thirst, dryness and wrinkling of skin, fall in plasma volume and blood pressure |
| until ICF and ECF are isotonic again | osmosis will move water out of the ICF and into ECF |
| sodium losses occur through | urine and perspiration |
| when sodium is too low | ADH and aldosternone is secreted |
| when sodium is too high | ANP is secreted |
| the rate of tubular secretion of potassium varies in response to what factor | aldosterone lovels |
| increase aldosterone will | increase sodium absorption and potassium secretion |
| hyperkalemia causes | cardiac arrhythmias |
| hypokalemia causes | muscular weakness and paralysis |
| calcium homeostasis reflects on | reserves in bones, rate of absorption in digestive tract, rate of loss at kidneys |
| parathyroid and calcitriol | RAISE concentrations; actions are opposed by calcitonin |
| hypocalcemia | osteoporosis,muscle cramps, muscle spasms, convulsions |
| if plasma is below 7.35 | acidemia, results in acidosis |
| if plasma is above 7.45 | alkalemia, results in alkalosis |
| acidosis can result in | a coma, cardiac failure, and circulatory collapse |
| volatile acid | can leave solution and enter atmosphere |
| fixed acids | most acids, produced by the body |
| organic acid | participants i n or by-products of aerobic metabolism |
| buffers | can provide(increases pH) or remove(decreases pH) H+ |
| amino acid/protein buffer system | depend on ability of amino acids to respond to changes in pH by accepting of releasing H+ |
| in hemoglobin buffer system it | absorb carbon dioxide from plasma, converts into carbonic acid |
| in hemoglobin buffer system it | bicarbonate ion moves into plasma |
| high levels of CO2 result in | low pH |
| low levels of CO2 result in | high pH |
| CO2 is or isnt an acid | is not |
| CO2 can be converted to | carbonic acid |
| carbonic acid bicarbonate buffer system role | is to prevent changes in pH caused by organic acids and fixed acids in ECF |
| carbonic acid bicarbonate buffer system limitations | only functions when respiratory and control centers work normal
limited by availability of bicarbonate ions |
| during acidosis | bicarbonate ions are released from storage |
| pulmonary compensation in acidosis | increased respiratory rate gets rid of excess C02 produced |
| renal compensation in acidosis | kidneys secrete and excrete excess hydrogen ions |
| protein buffers in acidosis | pick up excess H+ |
| pulmonary compensation in alkalosis | lower respiratory rate increases carbon dioxide levels |
| kidney compensation in alkalosis | kidneys secreate and excrete bicarbonate ions |
| protein buffers in alkalosis | release hydrogen ions |
| PCO2 rises | pH fall |
| PCO2 falls | pH rises |
| stimulation of chemoreceptors leads to | an INCREASE in RESPIRATORY RATE |
| chemoreceptors are stimulate if | high CO2 present or acidosis |
| renal contribution in pH is limited to | secretion of H+
activity of buffers
removal of CO2
reabsorption NA+ and HCO3 |
| when alkalosis or high pH develops | H+ secretion at kidneys decline
tuble cells dont reclaim bicarbonates
collectiond system transports HCO3 into tubular fluid releasing acid ino peritublar fluid |
| metabolic acidosis | production of large number of fixed or organic acids |
| hydrogen ions are liberated by what type of acids | fixed and organic |
| example of impaired ability to excrete at kidneys | glomerulonephritis |
| severe bicarbonate loss | chronic diarrhea |
| lactic acidosis | strenuous excercise |
| ketoacidosis | large quantities of ketone bodies, diabetes mellitus |
| metabolic alkalosis occurs when | HCO3 concentrations become elevated |
| metabolic alkalosis symtoms when | a person w/ prolong vomiting |
| what can cause metabolic alkalosis | increase amounts of anti acids |
| compensations for metabolic alkalosis involves | reduction in breathing rate ,increased loss of HCO3 in urine |
